The present invention relates to a brake regulator for a motor vehicle, of the type comprising a body pierced with a bore in which an annular gasket defines first and second chambers, of which the first is connected to the circuit of a master cylinder and the second to at least one brake motor, and a valve-forming piston movable in axial translational motion in an annular spacer bearing against the annular gasket, the piston having a diameter larger than that of the central orifice of the annular gasket forming a valve seat, and being equipped with a pusher which passes through the annular gasket and the first chamber and projects sealingly from the body.
Such a brake regulator is described in IT-B-1,183,952.
It is known that the characteristic curve of such a regulator is formed by a function of the outlet pressure in relation to the inlet pressure, that is to say the function of the pressure prevailing in the second chamber in relation to that prevailing in the first chamber. This curve consists of two straight segments of different gradients, connected at a point called the "cut-off point", from which the pressure increases less rapidly in the second chamber than in the first chamber.